Low noise synchronization of the frequency and phase of a DFB fiber laser and two fiber ring cavities was achieved based on a two-channel optical injection lock and phase lock loop. Two-channel modulation signals of different frequencies were adopted to extract the phase noise signals of the two fiber ring cavities. Finally, the lasers from the two fiber ring cavities were coherently combined in the closed loop of the control system owing to the synchronous frequency and phase. The power stability and polarization stability of the combined laser was improved under the optical injection lock and phase lock loop. The phase noise of the two cavities was 6.56×10−76.56 \times 10^{-7} rad/Hz1/2 and 1.34×10−61.34 \times 10^{-6} rad/Hz1/2 at 10 Hz; and 7.77×10−87.77 \times 10^{-8} rad/Hz1/2 and 1.35×10−71.35 \times 10^{-7} rad/Hz1/2 at 10 kHz. The total combined power was ~580 mW in the closed loop, and the entire system oscillated under a single frequency, providing excellent power scaling ability.

中文翻译：

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两个光纤环腔的频率同步和相干合成


基于双通道光注入锁和锁相环，实现了DFB光纤激光器和两个光纤环腔的频率和相位的低噪声同步。采用不同频率的两通道调制信号提取两个光纤环腔的相位噪声信号。最后，来自两个光纤环腔的激光由于频率和相位同步而在控制系统的闭环中相干组合。在光注入锁定和锁相环的作用下，组合激光器的功率稳定性和偏振稳定性得到提高。 10 Hz 时，两个腔体的相位噪声分别为 6.56×10−76.56 \times 10^{-7} rad/Hz1/2 和 1.34×10−61.34 \times 10^{-6} rad/Hz1/2； 10 kHz 时为 7.77×10−87.77 \times 10^{-8} rad/Hz1/2 和 1.35×10−71.35 \times 10^{-7} rad/Hz1/2。闭环总组合功率约为580 mW，整个系统在单一频率下振荡，提供出色的功率缩放能力。